Photonic bandgap fiber, including hollow core fiber, has the potential to replace conventional solid core optical fiber in numerous applications. Optical components utilizing this class of fiber are limited at this time.
Conventional couplers fall into three main classes: fused; lapped; and micro-optics. Micro-optic couplers are employed to split/combine two different wavelengths such as in a Wavelength Division Multiplexer or to split/combine orthogonal polarization states. Fused and lapped couplers are most commonly used for optical power redistribution.
There is an immediate need for a low loss coupler having hollow core fiber as a major component for resonator sensing applications.